I am looking at using Matter.js, a javascript physics engine, to have a bouncy ball in a simple game. It appears on their API that Matter might not have a property to change the bounciness of an object. Does anyone have any idea how I might go about implementing this?
Maybe you're looking for restitution?
https://brm.io/matter-js/docs/classes/Body.html#property_restitution
A Number that defines the restitution (elasticity) of the body. The value is always positive and is in the range (0, 1). A value of 0 means collisions may be perfectly inelastic and no bouncing may occur. A value of 0.8 means the body may bounce back with approximately 80% of its kinetic energy. Note that collision response is based on pairs of bodies, and that restitution values are combined with the following formula: